The word "kulak" originally referred to wealthy peasants in the Russian Empire. The original relevance of the word changed rapidly during the early 20th century. It simply defined people whom opposed the collectivization of the Soviet agriculture. In the social class hierarchy the "kulaks" were enemies of the Soviet peasants living below the standard.
From the 1920's until the mid-1930's the Soviets planned about major reforms, industrial and economic, modernizing the Soviet Karelia. However, they were lacking of laborers, good in quality. It was known that the support of socialism, communism and the labor movement was strong among the Finnish-Americans industrial workers, lumberjacks and miners. So, the Soviets started recruiting these people living in the North America. Until 1935 this recruitment generated so called "Return Migration" while approximately 10 000 Finnish-Americans from the US and Canada moved to the Soviet Karelia. The former Americans and Canadians established and constructed self-sufficient societies, small villages living in harmony in their new homeland. However, this trend was interrupted while from the mid-1930's Stalin renewed his plans considering the Soviet Karelia. The Finnish-Americans resisted the collectivization of their property and thus therefore they were considered as "kulaks".
In brief, an equivalent of a "kulak" outside the Russosphere can be described as an individual, opposing the prevailing social order.